A conventional method for the transmission of information via a satellite link is to convert the information into high frequency signals and to transmit them. In order to be able to transmit a large amount of information simultaneously, several selectable frequency bands of the total frequency spectrum suitable for a transmission are used for the transmission. These high frequency signals are transmitted from an earth station to a satellite and from the satellite to the receivers. The transmitted signals are converted and amplified in the satellites. Since the broadband amplifiers themselves cannot be implemented, the signals are broken down into relatively narrow frequency bands. These signals are amplified and subsequently combined to form the output signal and then transmitted.
In this connection, it is disadvantageous that a so-called skew occurs between the low, medium and high frequency signal components within a narrow band frequency band. The skew results in corrupted signals when the signals are subsequently combined and amplified. A conventional method for balancing the skew is to guide the signals via an equalizer having a circulator. The transmitted signal is injected in the circulator and sent to an output terminal via controlled reflections within the circulator. This reduces the group delay of the signal, i.e., the transmission time of the low, medium and high frequency signal components of a signal takes place in a shorter time interval. The use of a microwave equalizer in satellite communication systems is described in, for example, C. M. Kudsia, Synthesis of Optimum Reflection-Type Microwave Equalizers, RCA Review, September 1997, page 571 ff. Waveguide resonators or dielectric resonators having a downstream, short-circuited, double-tuned circuit filter are customarily used for this purpose. A disadvantage of such resonators is their relatively large size and, consequently, the use of a large number of such resonators in a satellite communication system, especially, in a satellite itself, is limited.
The manufacture of filters using superconductive planar technology is also generally known. In contrast to conventional filters and equalizers, they represent a considerable savings in space and weight.